So we don't know the whole story, but he was removed from the game, anyway? Not cool.
Thierry can do whatever he wants with his game, but ending a long and profitable (both emotionally and financially, presumably) friendship simply because of unproven allegations seems like a very short-sighted, fear-driven move.
They did it to protect the brand or whatever, but actions like this harm the brand in my eyes. Shows they care more about public perception than truth and justice. I, for one, will be removing Sea of Stars from my wishlist because of this.
Unless Thierry comes out and says he knew all along about The Completionist, which is literally the only way to justify such a preemptive sanction, he has irreparably harmed his integrity, IMO.